Wreckage near the site where a Hawker Hunter fighter jet crashed in ShorehamGetty

Police are warning that the number of victims in the Shoreham Airshow crash is likely to rise to at least 20 as they begin clear the wreckage from the disaster. Eleven people have so far been confirmed to have died after a plane came crashing down on the A27 on 22 August in West Sussex.

A clean-up operation of the 1950s Hunter Hawker likely to take several days will now begin at the site. Sussex Police said a crane is due to be brought in to lift the wreckage and it is quite possible emergency services will discover more bodies.

Following the tragedy, MPs and families of the victims have called all plane shows to be held over sea in order to avoid a repeat of the Shoreham crash. Sue Grimstone, mother of Worthing United footballer Mathew Grimstone, who died alongside teammate Jacob Schilt and personal trainer Matt Jones, told the Daily Telegraph. "It's such a waste. Air shows should be over the sea. It should never have been over that road."

Labour's Grahame Morris told the Daily Mirror: "If aircraft were limited to displaying over water it would mitigate the risk of casualties on the ground."

Fellow Labour MP Graham Stringer added: "I think when an event like this kills 11 people – and it's not the first time there have been fatalities at an airshow – there should be a serious look at the regulations with a view to tightening them up."

Sussex Police Assistant Chief Constable Steve Barry said: "This has been an enormously traumatic incident and our thoughts are with everyone who has been affected by the incident, from those who have suffered bereavement to those in the local community who are deeply shocked. I would like to pay tribute to colleagues in all of the emergency services, partner agencies and the organisers whose compassion and professionalism in the most extreme of circumstances has been widely commented upon.

"The scene of the incident is a large one, extending around 400 yards along the A27 and spilling off to the sides and just partly onto the airfield itself. We do know that no-one on the airfield attending the show was injured.

"As a result of the scale of the devastation, the recovery process is necessarily complex and thorough, and the work of those undertaking it cannot be understated. A crane will be brought in to lift the wreckage of the Hunter jet on Monday [24 August] and as we have already indicated, it is quite possible that we will discover more fatalities."

Police say the A27 will remain closed for several days while the clean up operation takes place REUTERS/Luke MacGregor

The pilot of the jet, 51-year-old Andy Hill, remains in a critical condition after he was pulled from the wreckage shortly after the crash. It is not known if he activated the ejector seat moments before impact.

An investigation is under way to try and determine if pilot error or a mechanical problem could have been the cause of the crash. An Air Accidents Investigation Branch spokesman said: "A preliminary report will be published when the initial stages of the investigation are completed. We ask if any members of the public with footage or photos of the crash could provide them to the AAIB as they could assist the investigation. They can do this by contacting: enquiries@aaib.gov.uk."

A Civil Aviation Authority spokesperson added: "The safety standards that must be met by all major civil air displays in the UK are among the very highest in the world. All aviation safety requirements are regularly reviewed to ensure they provide the highest possible levels of protection. Events of this nature are very rare, but we will now thoroughly examine the circumstances to establish if further improvements can be made."